Vanloads of illegal immigrants arriving by night at a disused warehouse? Drug addiction? Prostitution? Illegal organ transplanting? Child war conscripts? In many cases this is what human trafficking is. But the middle and upper classes in society can be culprits too, sometimes without even knowing it.

Domestic servitude is a form of exploitation that is more widespread than most people might think and one that needs to be recognised as a crime. A well-to-do family employing a maid, cash-in-hand with lodgings provided, may not seem like criminal activity. But it can be.

“Domestic servitude is one of the worst forms of trafficking in human beings,” says Maria Grazia Giammarinaro, OSCE special representative for combating trafficking in human beings. “It can take place because of the context of an ‘under-regulated sector.’” The domestic work sector needs better regulation.”

“The victims may not be paid at all or may be paid infrequently. Working hours can be as long as 19 hours a day. They are always at the disposal of the needs of the family; they can be called during the night to perform a duty, resulting in a lack of enjoying the natural biorhythm. They are very often subject to starvation, and may not be allowed to have any social contact outside the family,” adds Giammarinaro.

He said the first challenge is to recognise domestic servitude as a serious crime, different from minor violations of labour law: “When the personality of the person is devastated, when the dignity of the person is violated on a daily basis, we cannot talk about the violation of the labour law.”

Bridget Anderson, a researcher at the University of Oxford’s Centre on Migration, Policy and Society, said the many middle class people who do not consider themselves racist speak of domestic workers in a different light. She read an example, the words of a piano teacher from London, speaking of domestic workers:

“They’re foreign and they’re illegal and they’re scared and timid and so they’re not going to take up space. They’re going to be very, very small and that is generally easier to live with than someone who feels that this is their home. They’re in really bad situations… They’re terrified.”

Human trafficking has a global market value of $32 billion, according to United Nations estimates. It takes place across the globe, and in many cases goes unnoticed.

Sexual exploitation is the most-known form of trafficking people.

“Domestic work doesn’t need to be exploitative,” said Jenny Moss of Kalayaan, a London-based charity working with migrant domestic workers. “Domestic servitude on the other hand, is humiliating, is a violation of people’s dignity and is deeply traumatising.” There is demand for such services in the UK and domestic workers contribute to the country’s economy, Moss said.